A herbicidal composition comprising sesamex

Abstract

The present application belongs to the technical field of chemical herbicides, and particularly relates to a compound herbicide containing S-Isopropyl Methylcarbamate. The present application provides a compound herbicide containing S-Isopropyl Methylcarbamate, which is composed of S-Isopropyl Methylcarbamate-propynyl oxadiazolone microcapsule suspensible granules and propynyl oxadiazolone suspensible granules, so that: 1, part of the propynyl oxadiazolone is effectively microencapsulated, prolonging the effective period of weed control; 2, the compound herbicide has relatively high intensity of broadleaf weeds, gramineous weeds, and sedge weeds control effect in the early stage of the 100-day effective period, and can appropriately control various annual and perennial weeds throughout the effective period, ensuring outstanding weed control effect in corn, sorghum, peanut and other dry land crops.

Description

Technical Field

[0001] This invention belongs to the field of chemical herbicide technology, and particularly relates to a compound herbicide containing metolachlor. Background Technology

[0002] S-metolachlor is a selective pre-emergence herbicide, typically applied as a surface treatment before germination. S-metolachlor generally only distributes within 2 cm below the soil surface, while crop seeds are covered by soil at a greater depth; therefore, S-metolachlor has minimal impact on crop seeds.

[0003] S-metolachlor is mainly used to control various annual weeds and some broadleaf weeds. However, considering the comprehensiveness of weed control and the development of weed resistance after using a single herbicide, S-metolachlor is generally not used alone. Its common compound formulations include terbufos, propyzoxystrobin, and mesotrione.

[0004] The aforementioned propyne oxadiazon is a selective contact herbicide that works by being absorbed by seedlings or buds before or after weed emergence. It is mainly used to control various broadleaf weeds, grass weeds, and sedges.

[0005] For example, Chinese invention patent CN106538551A, published on March 29, 2017, discloses a microcapsule suspension of metolachlor and propyne oxadiazon and its preparation method. The preparation method includes: adding oil phase material to aqueous phase material and stirring to form an O / W emulsion; adding water-soluble shell material to the O / W emulsion and mixing it evenly, followed by polymerization to obtain metolachlor microcapsule suspension; adding propyne oxadiazon suspension to the metolachlor microcapsule suspension to obtain a metolachlor and propyne oxadiazon microcapsule suspension-suspension.

[0006] The compound herbicide in this invention patent includes S-metolachlor microcapsule suspension and propyzoxystrobin suspension. Therefore, its advantages include: 1. It controls a wider variety of weeds by combining two herbicides; 2. Compared to S-metolachlor used alone, the S-metolachlor microcapsule suspension has better slow-release effect, longer duration of action, and is relatively safer in production and use; 3. Similarly, propyzoxystrobin itself is a powder, and its suspension herbicide does not require the use of organic solvents, exhibiting excellent resistance to rain washout.

[0007] However, the biggest drawback of this microcapsule suspension-suspension agent in actual use, which is also the technical problem that this invention aims to solve, is:

[0008] The effective period of S-metolachlor microcapsule suspension is 80-120 days, while the effective period of propyzine suspension is generally around 30 days. Therefore, in the later stages of herbicide application, the combined herbicidal effect of S-metolachlor and propyzine is very limited.

[0009] Therefore, in summary, there is an urgent need for a compound herbicide consisting of metolachlor and propyzoxystrobin that provides primary control of various broadleaf and grass weeds in the early stages, and appropriate control of annual and sedge weeds in the later stages and throughout the entire effective period. Summary of the Invention

[0010] This invention provides a compound herbicide containing metolachlor, the raw material composition of which includes metolachlor-propyzoxyl microcapsule suspension particles and propyzoxyl suspension particles, such that: 1. Part of the propyzoxyl is effectively microencapsulated, extending its weed control effectiveness; 2. In the early stage of its approximately 100-day effective period, this compound herbicide has a relatively high control effect on broadleaf weeds, grass weeds, and sedge weeds, while throughout the entire effective period, it can appropriately control various annual and perennial weeds, ensuring outstanding weed control effects in dryland crops such as corn, sorghum, and peanuts.

[0011] The technical solution adopted by the present invention to solve the above problems is: a compound herbicide containing metolachlor, the raw material composition of which includes metolachlor-propyne oxadiazon microcapsule suspension particles and propyne oxadiazon suspension particles.

[0012] In this invention, the particle size of the microcapsule suspension particles of metolachlor-propyne oxadiazon is 3-4 μm, and the particle size of the suspension particles of propyne oxadiazon is 0.5-0.8 μm.

[0013] A further preferred technical solution is that the preparation method of the compound herbicide includes the following steps in sequence:

[0014] S1. Preparation of the oil phase by mixing: Add metolachlor technical, oil-soluble capsule material, and solvent to a stirred tank and stir to prepare the oil phase;

[0015] S2. Emulsion preparation: Water is added to the oil phase and stirred to obtain an O / W emulsion;

[0016] S3. Stirring and dispersing propyne oxadiazon: In the O / W emulsion, propyne oxadiazon technical material is added while stirring, so that propyne oxadiazon is dispersed in water and oil droplets to obtain a mixed emulsion;

[0017] S4. Interfacial polymerization: While stirring and cooling the mixed emulsion, water-soluble capsule material is added to carry out an interfacial polymerization reaction, and finally the compound herbicide including metolachlor-propyne oxadiazon microcapsule suspension particles and propyne oxadiazon suspension particles is obtained.

[0018] A further preferred technical solution is that, in S1, the oil-soluble shell material is any one of 2,6-toluene diisocyanate and diphenylmethane-4,4′-diisocyanate; and the solvent is any one of toluene, methanol, and ethyl acetate.

[0019] In this invention, both the technical grade metolachlor and the oil-soluble capsule material can be miscible with the solvent in any proportion.

[0020] A further preferred technical solution is that, in S2, the volume ratio of the oil phase to water is 1:(0.2-0.3).

[0021] In this invention, the above ratio is less than the commonly used ratio range, i.e., 1:0.5. This method allows as much of the propyne oxadiazon technical material as possible to enter the oil droplets, i.e., to enter the metolachlor.

[0022] Because there is a large interfacial tension at the interface between the S-metolachlor oil droplets and the aqueous phase, it is relatively difficult for the fine particulate propyzamide technical to overcome this interfacial tension and enter the S-metolachlor oil droplets. Therefore, a "favorable" condition with a relatively high proportion of oil droplets is set to ensure that sufficient and suitable propyzamide technical will eventually form the S-metolachlor-propyzamide microcapsule suspension particles, instead of all remaining in the aqueous phase and forming propyzamide suspension particles.

[0023] A further preferred technical solution is that, in S3, the stirring speed is 14000-18000 r / min and the stirring time is 10-15 min.

[0024] In this invention, the high-speed shearing operation described above has at least the following two advantages;

[0025] First, the S-metolachlor oil droplets are sheared and refined, so that the final S-metolachlor-propyne oxadiazon microcapsule suspension particles have the advantages of sufficiently fine particle size and sufficiently long suspension stability.

[0026] Second, stirring the propyne oxadiazon particles makes it relatively easier for them to enter and exit the S-metolachlor oil droplets. However, the overall effect is still to increase the amount of propyne entering the S-metolachlor oil droplets, that is, the above-mentioned entry effect is dominant.

[0027] A further preferred technical solution is that, in S4, the water-soluble shell material is any one of ethylenediamine, propylenediamine, and urea-formaldehyde resin prepolymer.

[0028] In this invention, the water-soluble and oil-soluble shell materials mentioned above are both raw materials required for microencapsulation operations using common interfacial polymerization methods, which can ensure the formation of a spherical shell with a high degree of coating and a suitable release rate of S-metolachlor on the surface of the oil droplets.

[0029] A further preferred technical solution is as follows: in S4, the stirring speed is 500-600 r / min, the temperature is reduced to 25-30℃ and then the cooling is stopped, the cooling range is ≤5℃ / min, and the interfacial polymerization reaction time is 2-3h.

[0030] In this invention, the relatively low stirring speed allows the water-soluble and oil-soluble shell materials to come into full contact and polymerize into a film, which is a necessary reaction condition for interfacial polymerization.

[0031] In general, the polymerization temperature in existing common interfacial polymerization methods is around 40°C. However, in this invention, the reaction temperature is 25-30°C. The purpose is to appropriately reduce the polymerization rate and extend the polymerization time, so that a small number of propyne oxadiazon particles can still enter the S-metolachlor oil droplets, ultimately increasing the absolute number of S-metolachlor-propyne oxadiazon microcapsule suspension particles, which is still relatively small.

[0032] Furthermore, if the reaction temperature is too low or the cooling rate is too fast, the completion rate of the most critical interfacial polymerization reaction may be reduced. Therefore, the temperature and cooling rate of the interfacial polymerization reaction were determined.

[0033] Finally, the interfacial polymerization reaction time required in this invention is extended by approximately 0.5 hours compared to the prior art. However, the number of target product microcapsule suspension particles of succinylmetholarin-propyneoxadiazon increases significantly during this time. Therefore, the above parameter settings and modifications are very valuable.

[0034] A further preferred technical solution is that, in step S4, after the interfacial polymerization reaction is completed, a dispersant, an antifreeze, a thickener, and an antifoaming agent are added to finally obtain the compound herbicide.

[0035] In this invention, the dispersant is sodium polycarboxylate, the antifreeze is glycerol, the thickener is magnesium aluminum silicate, and the defoamer is organosilicon.

[0036] A further preferred technical solution is that the weight ratio of metolachlor technical and propyzoxystrobin technical in the compound herbicide is (10-18):1.

[0037] In this invention, the compound herbicide is mainly composed of metolachlor, which ensures a more thorough and comprehensive weed control effect in cornfields, peanut fields, and soybean fields, which are mainly composed of annual weeds and broadleaf weeds.

[0038] A further preferred technical solution is that, in the compound herbicide, the weight of the propyne oxadiazon suspension particles accounts for 80-85% of the weight of the propyne oxadiazon technical material.

[0039] In this invention, the technical grade propyne oxadiazon is still mainly present as separately suspended propyne oxadiazon particles, which is consistent with the actual situation in weeding operations where a small number of sedges and other weeds occasionally emerge after propyne oxadiazon is sprayed.

[0040] Ultimately, in this compound herbicide, S-metolachlor can be released continuously for a long time, while propyzine can be effective in large quantities in the early stage and in small quantities in the later stage. This results in annual weeds being killed as soon as they sprout, while grass weeds are killed in a concentrated manner, allowing for relatively low-intensity supplementary control and killing afterwards. Detailed Implementation

[0041] The following description is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

[0042] Example 1

[0043] A compound herbicide containing metolachlor, comprising the following components by weight:

[0044] 25 portions of S-metholarin-propyneoxadiazon microcapsule suspension particles

[0045] One part of propyzinoxazine suspension particles

[0046] 8 parts deionized water

[0047] 2 parts of sodium polycarboxylate dispersant

[0048] 0.2 parts of glycerol antifreeze

[0049] 2 parts magnesium aluminum silicate thickener

[0050] 0.5 parts of silicone defoamer.

[0051] The preparation method of the compound herbicide includes the following steps in sequence:

[0052] S1. Preparation of the oil phase by mixing: Add metolachlor technical, oil-soluble capsule material, and solvent to a stirred tank and stir to prepare the oil phase;

[0053] S2. Emulsion preparation: Water is added to the oil phase and stirred to obtain an O / W emulsion;

[0054] S3. Stirring and dispersing propyne oxadiazon: In the O / W emulsion, propyne oxadiazon technical material is added while stirring, so that propyne oxadiazon is dispersed in water and oil droplets to obtain a mixed emulsion;

[0055] S4. Interfacial polymerization: While stirring and cooling the mixed emulsion, water-soluble capsule material is added to carry out an interfacial polymerization reaction, and finally the compound herbicide including metolachlor-propyne oxadiazon microcapsule suspension particles and propyne oxadiazon suspension particles is obtained.

[0056] In S1 of this embodiment, the oil-soluble shell material is 2,6-toluene diisocyanate, the solvent is toluene, and the oil phase is a miscible system.

[0057] In S2 of this embodiment, the volume ratio of the oil phase to water is 1:0.2, while the total amount of water required by the compound herbicide is larger than this amount of water. Therefore, deionized water needs to be added separately in the subsequent process.

[0058] In S3 of this embodiment, the stirring speed is 14000 r / min and the stirring time is 12 min.

[0059] In S4 of this embodiment, the water-soluble shell material is ethylenediamine, which can be directly polymerized with the oil-soluble shell material to form the microencapsulated "outer membrane" of the succinylmetholarin-propyneoxadiazon microcapsule suspension particles.

[0060] Furthermore, in step S4, the stirring speed is 550 r / min, the temperature is lowered to 25°C and then stopped, with a cooling rate ≤ 5°C / min, and the interfacial polymerization reaction time is 3 hours. After the interfacial polymerization reaction is completed, the dispersant, antifreeze, thickener, defoamer, and deionized water are added together or in batches according to the above-mentioned weight proportions, and the required amount of deionized water is replenished to finally obtain the compound herbicide.

[0061] Furthermore, in the above preparation method, the weight ratio of S-metolachlor technical grade to propyzamide technical grade is 17:1. The S-metolachlor-propyzamide microcapsule suspension particles achieve the above-mentioned weight ratio of 25:1 between microcapsule suspension particles and individual suspension particles only after combining the microencapsulated "outer membrane" and solvent, and containing and consuming a small amount of propyzamide.

[0062] Finally, before adding the dispersant, antifreeze, thickener, and defoamer, the "three-in-one" system of S-metolachlor-propyne oxadiazon microcapsule suspension particles, propyne oxadiazon suspension particles, and solvent water was sampled and membrane filtered to separate the microcapsule suspension particles and the individual suspension particles. The D90 of each and the weight ratio of propyne oxadiazon suspension particles to the initially added propyne oxadiazon technical material were measured. The specific data results are shown in Table 1 below.

[0063] Example 2

[0064] A compound herbicide containing metolachlor, comprising the following components by weight:

[0065] 28 samples of S-metholarin-propyneoxadiazon microcapsule suspension particles

[0066] One part of propyzinoxazine suspension particles

[0067] 9 parts deionized water

[0068] 3 parts of sodium polycarboxylate dispersant

[0069] 0.2 parts of glycerol antifreeze

[0070] 1 part magnesium aluminum silicate thickener

[0071] 0.5 parts of silicone defoamer.

[0072] The preparation method of the compound herbicide includes the following steps in sequence:

[0073] S1. Preparation of the oil phase by mixing: Add metolachlor technical, oil-soluble capsule material, and solvent to a stirred tank and stir to prepare the oil phase;

[0074] S2. Emulsion preparation: Water is added to the oil phase and stirred to obtain an O / W emulsion;

[0075] S3. Stirring and dispersing propyne oxadiazon: In the O / W emulsion, propyne oxadiazon technical material is added while stirring, so that propyne oxadiazon is dispersed in water and oil droplets to obtain a mixed emulsion;

[0076] S4. Interfacial polymerization: While stirring and cooling the mixed emulsion, water-soluble capsule material is added to carry out an interfacial polymerization reaction, and finally the compound herbicide including metolachlor-propyne oxadiazon microcapsule suspension particles and propyne oxadiazon suspension particles is obtained.

[0077] In S1 of this embodiment, the oil-soluble shell material is diphenylmethane-4,4′-diisocyanate, the solvent is methanol, and the oil phase is a miscible system.

[0078] In S2 of this embodiment, the volume ratio of the oil phase to water is 1:0.3, while the total amount of water required by the compound herbicide is larger than this amount of water. Therefore, deionized water needs to be added separately in the subsequent process.

[0079] In S3 of this embodiment, the stirring speed is 16000 r / min and the stirring time is 15 min.

[0080] In S4 of this embodiment, the water-soluble shell material is propylenediamine, which can be directly polymerized with the oil-soluble shell material to form the microencapsulated "outer membrane" of the succinylmetholarin-propyneoxadiazon microcapsule suspension particles.

[0081] Furthermore, in step S4, the stirring speed is 500 r / min, the temperature is lowered to 25°C and then stopped, with a cooling rate ≤ 5°C / min, and the interfacial polymerization reaction time is 3 hours. After the interfacial polymerization reaction is completed, the dispersant, antifreeze, thickener, defoamer, and deionized water are added together or in batches according to the above-mentioned weight proportions, and the required amount of deionized water is replenished to finally obtain the compound herbicide.

[0082] Furthermore, in the above preparation method, the weight ratio of S-metolachlor technical grade to propyzamide technical grade is 16:1. The S-metolachlor-propyzamide microcapsule suspension particles achieve the above-mentioned weight ratio of 28:1 of microcapsule suspension particles to individual suspension particles only after combining the microencapsulated "outer membrane" and solvent, and containing and consuming a small amount of propyzamide.

[0083] Finally, before adding the dispersant, antifreeze, thickener, and defoamer, the "three-in-one" system of S-metolachlor-propyne oxadiazon microcapsule suspension particles, propyne oxadiazon suspension particles, and solvent water was sampled and membrane filtered to separate the microcapsule suspension particles and the individual suspension particles. The D90 of each and the weight ratio of propyne oxadiazon suspension particles to the initially added propyne oxadiazon technical material were measured. The specific data results are shown in Table 1 below.

[0084] Example 3

[0085] A compound herbicide containing metolachlor, comprising the following components by weight:

[0086] 27 samples of S-metholarin-propyneoxadiazon microcapsule suspension particles

[0087] One part of propyzinoxazine suspension particles

[0088] 10 parts deionized water

[0089] 3 parts of sodium polycarboxylate dispersant

[0090] 0.5 parts of glycerol antifreeze

[0091] 1 part magnesium aluminum silicate thickener

[0092] 0.6 parts of silicone defoamer.

[0093] The preparation method of the compound herbicide includes the following steps in sequence:

[0094] S1. Preparation of the oil phase by mixing: Add metolachlor technical, oil-soluble capsule material, and solvent to a stirred tank and stir to prepare the oil phase;

[0095] S2. Emulsion preparation: Water is added to the oil phase and stirred to obtain an O / W emulsion;

[0096] S3. Stirring and dispersing propyne oxadiazon: In the O / W emulsion, propyne oxadiazon technical material is added while stirring, so that propyne oxadiazon is dispersed in water and oil droplets to obtain a mixed emulsion;

[0097] S4. Interfacial polymerization: While stirring and cooling the mixed emulsion, water-soluble capsule material is added to carry out an interfacial polymerization reaction, and finally the compound herbicide including metolachlor-propyne oxadiazon microcapsule suspension particles and propyne oxadiazon suspension particles is obtained.

[0098] In S1 of this embodiment, the oil-soluble shell material is diphenylmethane-4,4′-diisocyanate, the solvent is ethyl acetate, and the oil phase is a miscible system.

[0099] In S2 of this embodiment, the volume ratio of the oil phase to water is 1:0.3, while the total amount of water required by the compound herbicide is larger than this amount of water. Therefore, deionized water needs to be added separately in the subsequent process.

[0100] In S3 of this embodiment, the stirring speed is 16000 r / min and the stirring time is 10 min.

[0101] In S4 of this embodiment, the water-soluble capsule material is a urea-formaldehyde resin prepolymer, which can be directly polymerized with the oil-soluble capsule material to form the microencapsulated "outer membrane" of the succinylmetholarin-propyneoxadiazon microcapsule suspension particles.

[0102] Furthermore, in step S4, the stirring speed is 500 r / min, the temperature is lowered to 26°C and then stopped, with a temperature drop of ≤5°C / min, and the interfacial polymerization reaction time is 3 hours. After the interfacial polymerization reaction is completed, the dispersant, antifreeze, thickener, defoamer, and deionized water are added together or in batches according to the above-mentioned weight proportions, and the required amount of deionized water is replenished to finally obtain the compound herbicide.

[0103] Furthermore, in the above preparation method, the weight ratio of S-metolachlor technical grade to propyzamide technical grade is 14:1. The S-metolachlor-propyzamide microcapsule suspension particles achieve the above-mentioned weight ratio of 27:1 between microcapsule suspension particles and individual suspension particles only after combining the microencapsulated "outer membrane" and solvent, and containing and consuming a small amount of propyzamide.

[0104] Finally, before adding the dispersant, antifreeze, thickener, and defoamer, the "three-in-one" system of S-metolachlor-propyne oxadiazon microcapsule suspension particles, propyne oxadiazon suspension particles, and solvent water was sampled and membrane filtered to separate the microcapsule suspension particles and the individual suspension particles. The D90 of each and the weight ratio of propyne oxadiazon suspension particles to the initially added propyne oxadiazon technical material were measured. The specific data results are shown in Table 1 below.

[0105] Comparative Example 1

[0106] The compound herbicide in this comparative example differs from that in Example 1 in only one aspect:

[0107] By swapping the order of S3 and S4 in the preparation method, the propyne oxadiazon technical material is added after all the S-metolachlor microcapsule suspension particles have polymerized, and finally a microcapsule suspension-suspension herbicide including S-metolachlor microcapsule suspension particles and propyne oxadiazon suspension particles is obtained.

[0108] Similarly, samples were taken from the "three-in-one" system of S-metolachlor microcapsule suspension particles, propyzinoxazol suspension particles, and solvent water, and membrane filtration was performed to separate the microcapsule suspension particles from the individual suspension particles. The D90 of each was then measured. The specific data results are shown in Table 1 below.

[0109] Comparative Example 2

[0110] The compound herbicide in this comparative example differs from that in Example 2 in only one aspect:

[0111] By swapping the order of S3 and S4 in the preparation method, the propyne oxadiazon technical material is added after all the S-metolachlor microcapsule suspension particles have polymerized, and finally a microcapsule suspension-suspension herbicide including S-metolachlor microcapsule suspension particles and propyne oxadiazon suspension particles is obtained.

[0112] Similarly, samples were taken from the "three-in-one" system of S-metolachlor microcapsule suspension particles, propyzinoxazol suspension particles, and solvent water, and membrane filtration was performed to separate the microcapsule suspension particles from the individual suspension particles. The D90 of each was then measured. The specific data results are shown in Table 1 below.

[0113] Comparative Example 3

[0114] The compound herbicide in this comparative example differs from that in Example 3 in only one aspect:

[0115] By swapping the order of S3 and S4 in the preparation method, the propyne oxadiazon technical material is added after all the S-metolachlor microcapsule suspension particles have polymerized, and finally a microcapsule suspension-suspension herbicide including S-metolachlor microcapsule suspension particles and propyne oxadiazon suspension particles is obtained.

[0116] Similarly, samples were taken from the "three-in-one" system of S-metolachlor microcapsule suspension particles, propyzinoxazol suspension particles, and solvent water, and membrane filtration was performed to separate the microcapsule suspension particles from the individual suspension particles. The D90 of each was then measured. The specific data results are shown in Table 1 below.

[0117] Testing and Experiment

[0118] Five samples of 50 ml each were taken from each of the three embodiments and three comparative examples, for a total of 30 samples. The D90 data and weight ratio of the embodiments were then tested, as well as the D90 data of the comparative examples. The average value was then taken, and the results are shown in Table 1 below.

[0119] Table 1 (In the table, the microcapsule suspension particles of succinate-propyne oxadiazon are the microcapsule suspension particles of succinate-propyne oxadiazon, and the ratio of propyne suspension particles to propyne technical is the weight ratio of propyne oxadiazon suspension particles to the propyne technical initially added.)

[0120]

[0121] Weed control trial

[0122] In the above three examples and three comparative examples, six herbicide samples of 100ml / part and 300ml / part were taken respectively, and then these 12 herbicide samples were sprayed in 12 cornfields of approximately 1 acre each. The water dilution ratio of the herbicide was uniformly 5 catties of water / 10 ml of herbicide.

[0123] Finally, the approximate number of annual and perennial weeds in the cornfield was observed at 5, 20, 40, 80 and 100 days after herbicide spraying, and the data were recorded in Table 2 below.

[0124] Among them, S-metolachlor is mainly used to control annual weeds, and the control effect is recorded based on the residual amount of barnyard grass, crabgrass, and cocklebur. Propylene oxadiazon is mainly used to control perennial weeds, and the control effect is recorded based on the residual amount of plantain, nutgrass, and sedge.

[0125] Table 2 (In the table, only data with obvious weed residue are recorded, indicated by X)

[0126]

[0127] Conclusion Analysis

[0128] First, whether or not the propyne oxadiazon particles themselves enter the S-metolachlor oil droplets has almost no effect on the particle size of the S-metolachlor-propyne oxadiazon microcapsule suspension particles.

[0129] Secondly, the compound herbicide in the above embodiments, even with various enhancement methods, can only "inject" 15-20 wt% of propyzinoxadiazon into S-metolachlor oil droplets, ultimately forming S-metolachlor-propyzinoxadiazon microcapsule suspension particles.

[0130] Third, in relatively small-dose spraying operations, when propyzin is used only as a single suspended particulate, perennial weeds will re-emerge in a certain amount after 80-100 days. Its effective period of control over perennial weeds is relatively short, corresponding to the five "X"s on the right side of Table 2 above.

[0131] Fourth, in relatively small-dose spraying operations, a small portion of propyzoxystrobin is released in the form of S-metolachlor-propyzoxystrobin microcapsule suspension particles, ensuring that even in the later stages of the S-metolachlor residual effect at 80-100 days, it can still kill some of the re-emerging perennial weeds, which is very advantageous.

[0132] Fifth, as mentioned in points three and four above, when the dosage of propyne oxadiazon increases, the harmful problem of its unsatisfactory killing effect on perennial weeds in the later stage will not occur at all. However, this does not negate the advantage of the above embodiments that the control effect on perennial weeds is quite good and only a small dose of herbicide is required.

[0133] Sixth, in Example 2, a significant number of annual weeds re-emerged after 100 days. This data is an occasional phenomenon and has no analytical value.

[0134] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various modifications can be made without departing from the spirit of the present invention. These are all non-inventive modifications, and are protected by patent law as long as they fall within the scope of the claims of the present invention.

Claims

1. A compound herbicide containing S-metolachlor, characterized in that: The raw material composition includes microcapsule suspensions of metolachlor-propyne oxadiazon and propyne oxadiazon suspension particles. The preparation method of the compound herbicide includes the following steps in sequence: S1. Preparation of the oil phase by mixing: Add metolachlor technical, oil-soluble capsule material, and solvent to a stirred tank and stir to prepare the oil phase; S2. Emulsion preparation: Water is added to the oil phase and stirred to obtain an O / W emulsion; S3. Stirring and dispersing propyne oxadiazon: In the O / W emulsion, propyne oxadiazon technical material is added while stirring, so that propyne oxadiazon is dispersed in water and oil droplets to obtain a mixed emulsion; S4. Interfacial polymerization: While stirring and cooling the mixed emulsion, water-soluble capsule material is added to carry out an interfacial polymerization reaction, ultimately obtaining the compound herbicide including metolachlor-propyzoxylate microcapsule suspension particles and propyzoxylate suspension particles. In S3, the stirring speed is 14000-18000 r / min, and the stirring time is 10-15 min. In the aforementioned compound herbicide, the weight of propyzoxystrobin suspension particles accounts for 80-85% of the weight of propyzoxystrobin technical grade. The particle size of the microcapsule suspension particles of metolachlor-propyne oxadiazon is 3-4 μm, and the particle size of the propyne oxadiazon suspension particles is 0.5-0.8 μm.

2. The compound herbicide containing metolachlor according to claim 1, characterized in that: In S1, the oil-soluble shell material is any one of 2,6-toluene diisocyanate and diphenylmethane-4,4′-diisocyanate; the solvent is any one of toluene, methanol, and ethyl acetate.

3. The compound herbicide containing metolachlor according to claim 1, characterized in that: In S2, the volume ratio of the oil phase to water is 1:(0.2-0.3).

4. A compound herbicide containing metolachlor according to claim 1, characterized in that: In S4, the water-soluble shell material is any one of ethylenediamine, propylenediamine, and urea-formaldehyde resin prepolymer.

5. A compound herbicide containing metolachlor according to claim 1, characterized in that: In S4, the stirring speed is 500-600 r / min, and the temperature is reduced to 25-30℃ before cooling is stopped. The cooling rate is ≤5℃ / min, and the interfacial polymerization reaction time is 2-3 h.

6. A compound herbicide containing metolachlor according to claim 1, characterized in that: In step S4, after the interfacial polymerization reaction is completed, a dispersant, antifreeze, thickener, and defoamer are added to finally obtain the compound herbicide.

7. A compound herbicide containing metolachlor according to claim 1, characterized in that: In the compound herbicide, the weight ratio of S-metolachlor technical and propyoxaflutole technical is (10-18):1.

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